#2442: Merged files from trunk and updated project file. Implemented missing operations in the CompiledTreeInterpreter: Integral, Derivative, Lag, TimeLag. Adapted lambda signature to accept an array of List<double> in order to make it easier to work with compiled trees. Changed value parameters to fixed value parameters and adjusted interpreter constructors and after serialization hooks. Removed function symbol.

From the performance point of view, compiling the tree into a lambda accepting a double[][] parameter (an array of arrays for the values of each double variable), accessed with Expression.ArrayIndex is the fastest, but it can be cumbersome to provide the data as a double[][]. Therefore the variant with List<double>[] was chosen. Internally, for each variable node the List's underlying double array is used, result in an overall decent speed compromise.

11/04/15:

#2269 Added ReduceToPopulationSize parameter to control if the population is reduced to the PopulationSize after elder migration (default) or the layer can have more than PopulationSize individuals until the next generation.